An athlete is working out in the weight room. He steadily holds 50 kilograms above his head for 10 seconds. Which statement is true about this situation? The athlete isn’t doing any work because he doesn’t move the weight. The athlete isn’t doing any work because he doesn’t hold the weight long enough. The athlete is doing work because he prevents the weight from falling downward. The athlete is doing work because 50 kilograms is a significant load to lift.
But if he passed high school physics, then he may remember that
'work' in physics means (force) x (distance). If there's no distance,
then there's no work.
He realizes that he isn’t doing any work because he's not moving the weight.
In 2004 astronomers reported the discovery of a large Jupiter-sized planet orbiting very close to the star HD 179949 (hence the term "hot Jupiter"). The orbit was just 19 the distance of Mercury from our sun, and it takes the planet only 3.09 days to make one orbit (assumed to be circular). What is the mass of the star? Express your answer (a)in kilograms and (b)as a multiple of our sun's mass.
Use Kepler's 3rd Law
T^2 = k R^3
where k = 4(pi)^2/ GM
G =gravitational constant = 6.67300 × 10-11 m3 kg-1 s-2
M = mass of this new planet
pi = 3.14159265
T =3.09 days = 266976 seconds
R = (579,000,000km)/9 = 64333333.3 km
Solve Kepler's 3rd Law for M. Your answer will be in kg
mass of the sun = 1.98892 × 10^30 kilograms
Form the ratio
A snowmobile has an initial velocity of 3.0 m/s Part 1: If it accelerates at the rate of 0.5 m/s/s for 7.0 sec, what is the final vel.? Part 2: If it accelerates at the rate of -0.60m/s/s, how long will it take to reach a complete stop?
As we know that
here we know that
so we will have
if finally the snowmobile comes to rest
So here we can say that
so now we have
here, F = 25 N
s = 3 m
Substitute it into the expression,
W = 25 * 3
W = 75 Joule
So, your final answer is 75 J
Hope this helps!
the answer is d i just took the test k 12 right
There are 2 ways of solving this question
First is to use formula which connects starting speed, acceleration (which we would calculate from graph where we can see how speed changes) and time to calculate traveled distance.
S = V0 * t + 1/2*a*t^2
acceleration a is a = -4m/s^2
S(t=3s) = 18
On this value we add 12 initial meters of distance and we get S(t=3s) = 30 meters
For t=4s we get
S = 16 m
Plus initial distance of 12 m we get 30 meters
Answers are 30 and 28 meters.
second way is to find surface of graph bellow speed line for 3 and 4 seconds...
Please help! Find the tension in each cord in the figure if the weight of the suspended object is w = 210N A) Find the tension in the cord A for system (b). B) Find the tension in the cord B for system (b).
- T a * cos 60° + T b * sin 45° - 210 N = 0
- T a * sin 60° + Tb cos 45° = 0
- 1/2 T a + √2 / 2 T b = 210 N
- √3 / 2 T a + √ 2 / 2 T b = 0 / * ( - 1 )
- 1/2 T a + √2 / 2 T b = 210 N
√ 3 / 2 T a - √2 / 2 T b = 0
T a ( √3 / 2 - 1 / 2 ) = 210 N
0.366 T a = 210 N
T a = 210 N : 0.366
1 ) T a = 573.77 N
Ta * √3 / 2 = T b * √ 2 / 2
T b = ( 573.77 * 1.732 ) : 1.4142
2 ) T b = 702.7 N
When a bullet is fired from a gun, what is true about the momentum? The gun has more momentum than the bullet, so the momentum is not conserved. The bullet and gun have equal momenta in opposite directions, so the system's momentum is conserved. The bullet has more momentum than the gun, so the momentum is not conserved. The bullet and the gun have equal momenta in the same direction, so the system's momentum is conserved.
Force times Mass equals Acceleration.
The answer is TRUE.
If the mass increases the number on the left side of the equation increases, thus increasing the right side as well.
Which statement is NOT true? a. water plays an important role in the control of body temperature b. water helps carry nutrients to cells and waste products away from cells c. people need a minimum of 10-12 glasses of water each day d. soups, fruits, vegetables, and meats are sources of water
Crustal plates scrape and slide past each other along faults at their boundaries. For example, the Pacific and North American Plates slide past each other along the San Andreas Fault in northern California. What natural hazard usually results when crustal plates scrape and slide past one another? A. hurricanes B. tsunamis C. tornadoes D. earthquakes 50 POINTS!
The answer is D I just took the test on study island
and there is an explanation
When crustal plates scrape and slide past one another, they release built-up energy. This energy travels through the Earth as earthquakes.
he gave the correct answer its just we had options when we were doing this assignment so thanks for going in depth
(0.544881 mol C) × (12.01078 g C/mol) = 6.54445 g C
(4.91 g H2O) / (18.01532 g H2O/mol) × (2 mol H / 1 mol H2O) = 0.54509 mol H
(0.54509 mol H) × (1.007947 g H/mol) = 0.54942 g H
10 g total - 6.54445 g C - 0.54942 g H = 2.90613 g O
(2.90613 g O) / (15.99943 g O/mol) = 0.18164 mol O
Divide by the smallest number of moles:
(0.544881 mol C) / 0.18164 mol = 2.9998
(0.54509 mol H) / 0.18164 mol = 3.0009
(0.18164 mol O) / 0.18164 mol = 1.0000
Round to the nearest whole number to find the empirical formula:
Which scenario relates to Mayer and Salovey’s third component of emotional intelligence (regulating emotions)? A. gauging a friend’s anxiety in the absence of verbal cues B. reacting pleasantly to a friend’s practical joke C. understanding a friend’s problems and providing support D. determining the underlying cause of a friend’s nervous breakdown E. asking for a friend’s suggestion when working through a conflict
Option C i.e understanding a friend's problems and providing support is the correct answer.
Mayer and Salovey’s third component of emotional intelligence (regulating emotions) is the ability to Understand Emotions. So understanding a friend’s problems and providing support is the scenario relates to Mayer and Salovey’s third component of emotional intelligence (regulating emotions)
What do the yellow arrows in this illustration represent? A. movement of earth’s tectonic plates B. convection in the asthenosphere C. convection in the lithosphere D. direction of earth's magnetic field
What happens when the electron moves from the first energy level to the second energy level? Energy is absorbed, and an emission line is produced. Energy is released, and an emission line is produced. Energy is absorbed by the atom. Energy is lost from the atom.
Emission lines occur only in the case of transitions from higher to lower energy levels in which energy is emitted.
PLEASE HELP FAST??!! Which statement is true about the electromagnetic spectrum? A. The visible Spectrum includes radio waves, light and gamma rays. B. Same wave lengths of light corresponding to different colors. C. It contains a spectrum of visible light plus a wide array of nonvisible forms of radiation. D. The waves travel at a speed of 2.998 *10^5 m/s
The electromagnetic spectrum contains visible light along with many other components such as radio waves, microwaves, ultraviolet rays and gamma rays.
A student hangs a mass of 150 g on a force table at an angle of 150 degrees . If she then hangs a mass of 220 g at 270 degrees. A) at what angle should she hang a mass of 195 g so that the ring is in equilibrium? B) Draw the vectors
cosΘ = 0.666
Θ = ± 48º
150g*sin150 + 220g*sin270 + 195g*sinΘ = 0
sinΘ = 0.744
Θ = 48º
E = nhc / λ
Also, Power = Energy / time
E = 20 x 10⁻³ x 60 x 60
E = 108 J
108 = (2.29 x 10²⁰ x 6.63 x 10⁻³⁴ x 3 x 10⁸) / λ
λ = 4.22 x 10⁻⁷ m
Which of the following might be considered a viable application of a radioactive tracer? It can be more then one? A) adding a stream of radioisotopes to waste water to examine where pollution goes when it flows into the ocean B) embedding a radioactive plug in a valuable necklace so that its location can be determined using a Geiger counter C) placing radioactive sources around a room to trace the location of people as they move through the room d.) filling a pipeline with radioactive gas to see if it contains any leaks